Influence of Exogenous 28-Homobrassinolide Optimized Dosage and EDAH Application on Hormone Status, Grain Filling, and Maize Production

Abstract

Exogenously applied phytohormones improve the endosperm cells and establish greater kernel sink capacity and grain filling, improving grain yield. In this study, 28-Homobrassinolide (HBR) dosages (20, 25, and 30 mg a. i. ha−1) were applied separately at the silking stage under controlled conditions, and EDAH (a mixture of ethephon and diethyl aminoethyl hexanoate) dosage of 90 g a. i. ha−1 was sprayed at the jointing stage to enhance the lodging resistance. Our objective was to investigate whether the application of HBR under controlled conditions or with EDAH could enhance the grain filling rate by regulating endogenous hormones. The results showed that HBR at the silking stage significantly increased endogenous hormones (ABA, IAA, Z+ZR), hampered leaf senescence, enhanced photosynthetic, improved dry matter accumulation in grains, and increased the grain-filling period, filling rate, and thousand-grains weight. Additionally, HBR 25 and 30 mg a. i. ha−1 increased the final yield by 9.9% and 19.5% compared to the control (CK) in 2020 and 14.1% and 18.95% in 2021, respectively. There was no significant difference between the results obtained from HBR-controlled and EDAH treatments at the jointing stage. Thus, we conclude that spraying HBR 25~30 mg a. i. ha−1 under controlled conditions may increase the grain yield under normal weather conditions. In adverse weather conditions and heavy wind, spraying EDAH 90 g a. i. ha−1 at the jointing stage and HBR 30 mg a. i. ha−1 at the silking stage can enhance maize production.

Zinc-oxide nanoparticles ameliorated the phytotoxic hazards of cadmium toxicity in maize plants by regulating primary metabolites and antioxidants activity

“…The resemblance between the non-essential element Cd and the necessary nutrient Zn increased the zinc relevance in the soil-plant relationship (Rizwan et al, 2019a). Due to the incompatible actions of these metals on each other, a sufficient amount of Zn in the soil may interact with Cd and limit plant buildup (Huang et al, 2019;Hussain et al, 2022b;Hussain et al, 2022c). The photosynthetic machinery is regarded as the chief indicator of heavy metal-induced poisonousness in plants (Faseela et al, 2020).…”

“…Similarly, Cd reduced the growth, dry biomass, and morphological characteristics of Ocimum basilicums (Fattahi et al, 2019) and significantly reduced Vigna radiata production (Rehman et al, 2022). Cd stress increases the production of reactive oxygen species (ROS) and changes plants' antioxidant potential (Yizhu et al, 2020;Hussain et al, 2022a). In plant biology, ROS serves as cell signaling molecules and induces oxidative stress depending on its concentration (Mittler, 2017).…”

Modeling Spring Maize Grain Filling under Film Mulching and Nitrogen Application in a Cold and Arid Environment

“…drought stress [34], plant hormones [35], nitrogen fertilizer management [36], and maize varieties [37]. However, there is little research on the dynamic changes in maize grain filling when different plastic-film mulching and nitrogen application levels are combined, and logistic models [27,33] are often used for the fitting analysis of the maize grain-filling process.…”

“…Reasonable nitrogen fertilizer application can affect the grain-filling process of corn, promote ear development, increase grain weight, and ultimately improve 100-grain quality and yield. At present, research into the process of maize grain filling mainly focuses on high temperature and drought stress [34], plant hormones [35], nitrogen fertilizer management [36], and maize varieties [37]. However, there is little research on the dynamic changes in maize grain filling when different plastic-film mulching and nitrogen application levels are combined, and logistic models [27,33] are often used for the fitting analysis of the maize grain-filling process.…”